diff --git a/changelog.txt b/changelog.txt
index 084ad4d..c93e8c3 100644
--- a/changelog.txt
+++ b/changelog.txt
@@ -1,3 +1,11 @@
+
+================================================================================
+ v1.1.1
+================================================================================
+Added: Expiration option, expires works with minutes,
+  or you can send a datetime and set the option
+  `isExpiresDate` to true.
+
 ================================================================================
  v1.1.0
 ================================================================================
diff --git a/package-lock.json b/package-lock.json
index 047a49f..c935ee3 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -1,6 +1,6 @@
 {
   "name": "immortal-db",
-  "version": "1.1.0",
+  "version": "1.1.1",
   "lockfileVersion": 1,
   "requires": true,
   "dependencies": {
diff --git a/package.json b/package.json
index f663056..321d293 100644
--- a/package.json
+++ b/package.json
@@ -1,7 +1,7 @@
 {
   "name": "immortal-db",
   "private": false,
-  "version": "1.1.0",
+  "version": "1.1.1",
   "main": "dist/immortal-db.js",
   "module": "src/index.js",
   "types": "immortal-db.d.ts",
diff --git a/src/cookie-store.js b/src/cookie-store.js
index 4792cbe..f03b436 100644
--- a/src/cookie-store.js
+++ b/src/cookie-store.js
@@ -17,8 +17,8 @@ const DEFAULT_COOKIE_TTL = 365 // Days.
 // https://tools.ietf.org/html/draft-west-cookie-incrementalism-00 for
 // details on SameSite and cross-origin behavior.
 const CROSS_ORIGIN_IFRAME = amIInsideACrossOriginIframe()
-const DEFAULT_SECURE = (CROSS_ORIGIN_IFRAME ? true : false)
-const DEFAULT_SAMESITE = (CROSS_ORIGIN_IFRAME ? 'None' : 'Lax')
+const DEFAULT_SECURE = !!CROSS_ORIGIN_IFRAME
+const DEFAULT_SAMESITE = CROSS_ORIGIN_IFRAME ? 'None' : 'Lax'
 
 function amIInsideACrossOriginIframe () {
   try {
@@ -28,7 +28,7 @@ function amIInsideACrossOriginIframe () {
     // If inside a cross-origin iframe, raises: Uncaught
     // DOMException: Blocked a frame with origin "..." from
     // accessing a cross-origin frame.
-    return !Boolean(window.top.location.href)
+    return !window.top.location.href
   } catch (err) {
     return true
   }
@@ -36,9 +36,10 @@ function amIInsideACrossOriginIframe () {
 
 class CookieStore {
   constructor ({
-      ttl = DEFAULT_COOKIE_TTL,
-      secure = DEFAULT_SECURE,
-      sameSite = DEFAULT_SAMESITE} = {}) {
+    ttl = DEFAULT_COOKIE_TTL,
+    secure = DEFAULT_SECURE,
+    sameSite = DEFAULT_SAMESITE,
+  } = {}) {
     this.ttl = ttl
     this.secure = secure
     this.sameSite = sameSite
@@ -48,23 +49,45 @@ class CookieStore {
 
   async get (key) {
     const value = Cookies.get(key)
+    console.log(Cookies.expires)
     return typeof value === 'string' ? value : undefined
   }
 
-  async set (key, value) {
-    Cookies.set(key, value, this._constructCookieParams())
+  async set (key, value, options = { expires: 0, isExpiresDate: false }) {
+    let opts = {}
+    if (options && options.expires) {
+      opts.expires = options.isExpiresDate
+        ? new Date(options.expires)
+        : new Date(new Date().getTime() + options.expires * 60 * 1000)
+    }
+    Cookies.set(key, value, this._constructCookieParams(opts))
   }
 
   async remove (key) {
     Cookies.remove(key, this._constructCookieParams())
   }
 
-  _constructCookieParams () {
-    return {
-      expires: this.ttl,
+  _constructCookieParams (
+    options = {
+      expires: this.tll,
+      secure: this.secure,
+      sameSite: this.sameSite,
+    },
+  ) {
+    const opts = {
+      expires: this.tll,
       secure: this.secure,
       sameSite: this.sameSite,
     }
+
+    const keys = Object.keys(opts)
+    for (let i = 0; i < keys.length; i++) {
+      if (options[keys[i]]) {
+        opts[keys[i]] = options[keys[i]]
+      }
+    }
+
+    return opts
   }
 }
 
diff --git a/src/index.js b/src/index.js
index e1a2faf..9efecd3 100644
--- a/src/index.js
+++ b/src/index.js
@@ -14,7 +14,7 @@ import { LocalStorageStore, SessionStorageStore } from './web-storage'
 
 const cl = console.log
 const DEFAULT_KEY_PREFIX = '_immortal|'
-const WINDOW_IS_DEFINED = (typeof window !== 'undefined')
+const WINDOW_IS_DEFINED = typeof window !== 'undefined'
 
 // Stores must implement asynchronous constructor, get(), set(), and
 // remove() methods.
@@ -92,21 +92,25 @@ class ImmortalStorage {
     // classes (whose definitions are synchronous) must be accepted in
     // addition to instantiated store objects.
     this.onReady = (async () => {
-      this.stores = (await Promise.all(
-        stores.map(async StoreClassOrInstance => {
-          if (typeof StoreClassOrInstance === 'object') { // Store instance.
-            return StoreClassOrInstance
-          } else { // Store class.
-            try {
-              return await new StoreClassOrInstance() // Instantiate instance.
-            } catch (err) {
-              // TODO(grun): Log (where?) that the <Store> constructor Promise
-              // failed.
-              return null
+      this.stores = (
+        await Promise.all(
+          stores.map(async StoreClassOrInstance => {
+            if (typeof StoreClassOrInstance === 'object') {
+              // Store instance.
+              return StoreClassOrInstance
+            } else {
+              // Store class.
+              try {
+                return await new StoreClassOrInstance() // Instantiate instance.
+              } catch (err) {
+                // TODO(grun): Log (where?) that the <Store> constructor Promise
+                // failed.
+                return null
+              }
             }
-          }
-        }),
-      )).filter(Boolean)
+          }),
+        )
+      ).filter(Boolean)
     })()
   }
 
@@ -125,6 +129,28 @@ class ImmortalStorage {
       }),
     )
 
+    const expiresValues = await Promise.all(
+      this.stores.map(async store => {
+        try {
+          return await store.getExpires(prefixedKey)
+        } catch (err) {}
+      }),
+    )
+
+    const countedExpires = Array.from(countUniques(expiresValues).entries())
+    countedExpires.sort((a, b) => a[1] <= b[1])
+    let expires
+    const [firstVal, firstCo] = arrayGet(countedExpires, 0, [undefined, 0])
+    const [secondVal, secondCo] = arrayGet(countedExpires, 1, [undefined, 0])
+    if (
+      firstCo > secondCo ||
+      (firstCo === secondCo && firstVal !== undefined)
+    ) {
+      expires = firstVal
+    } else {
+      expires = secondVal
+    }
+
     const counted = Array.from(countUniques(values).entries())
     counted.sort((a, b) => a[1] <= b[1])
 
@@ -141,7 +167,7 @@ class ImmortalStorage {
     }
 
     if (value !== undefined) {
-      await this.set(key, value)
+      await this.set(key, value, { expires, isExpiresDate: true })
       return value
     } else {
       await this.remove(key)
@@ -149,7 +175,7 @@ class ImmortalStorage {
     }
   }
 
-  async set (key, value) {
+  async set (key, value, options = { expires: 0 }) {
     await this.onReady
 
     key = `${DEFAULT_KEY_PREFIX}${key}`
@@ -157,7 +183,7 @@ class ImmortalStorage {
     await Promise.all(
       this.stores.map(async store => {
         try {
-          await store.set(key, value)
+          await store.set(key, value, options)
         } catch (err) {
           cl(err)
         }
diff --git a/src/indexed-db.js b/src/indexed-db.js
index 3e709cc..6841973 100644
--- a/src/indexed-db.js
+++ b/src/indexed-db.js
@@ -17,10 +17,16 @@ import {
 
 const DEFAULT_DATABASE_NAME = 'ImmortalDB'
 const DEFAULT_STORE_NAME = 'key-value-pairs'
+const DEFAULT_EXPIRES_DB_NAME = 'ImmortalDBExp'
 
 class IndexedDbStore {
-  constructor (dbName = DEFAULT_DATABASE_NAME, storeName = DEFAULT_STORE_NAME) {
+  constructor (
+    dbName = DEFAULT_DATABASE_NAME,
+    storeName = DEFAULT_STORE_NAME,
+    expiresDBName = DEFAULT_EXPIRES_DB_NAME,
+  ) {
     this.store = new Store(dbName, storeName)
+    this.expiresStore = new Store(expiresDBName, storeName)
 
     return (async () => {
       // Safari throws a SecurityError if IndexedDB.open() is called in a
@@ -34,6 +40,7 @@ class IndexedDbStore {
       // Safari. Push the fix(es) upstream.
       try {
         await this.store._dbp
+        await this.expiresStore._dbp
       } catch (err) {
         if (err.name === 'SecurityError') {
           return null // Failed to open an IndexedDB database.
@@ -47,17 +54,49 @@ class IndexedDbStore {
   }
 
   async get (key) {
+    const val = await this.getExpires(key)
+    if (val && val <= new Date().getTime()) {
+      await this.remove(key)
+    }
+
     const value = await idbGet(key, this.store)
     return typeof value === 'string' ? value : undefined
   }
 
-  async set (key, value) {
+  async set (key, value, options = { expires: 0, isExpiresDate: false }) {
     await idbSet(key, value, this.store)
+
+    if (options && options.expires) {
+      // If expire exists, update or add it.
+      await idbSet(
+        key,
+        options.isExpiresDate
+          ? options.expires.toString()
+          : new Date(new Date().getTime() + options.expires * 60 * 1000)
+              .getTime()
+              .toString(),
+        this.expiresStore,
+      )
+    } else {
+      // If it doesn't exist, remove any existing expiration
+      await idbRemove(key, this.expiresStore)
+    }
+  }
+
+  async getExpires (key) {
+    const value = await idbGet(key, this.expiresStore)
+    return typeof value === 'string' ? +value : 0
   }
 
   async remove (key) {
+    await idbRemove(key, this.expiresStore)
     await idbRemove(key, this.store)
   }
 }
 
-export { IndexedDbStore, DEFAULT_DATABASE_NAME, DEFAULT_STORE_NAME }
+export {
+  IndexedDbStore,
+  DEFAULT_DATABASE_NAME,
+  DEFAULT_STORE_NAME,
+  DEFAULT_EXPIRES_DB_NAME,
+}
diff --git a/src/web-storage.js b/src/web-storage.js
index 59270f9..09e7a47 100644
--- a/src/web-storage.js
+++ b/src/web-storage.js
@@ -8,24 +8,53 @@
 // License: MIT
 //
 
+const EXPIRES_PREFIX = 'exp_'
+
 class StorageApiWrapper {
-  constructor (store) {
+  constructor (store, expiresPrefix = EXPIRES_PREFIX) {
     this.store = store
+    this.expiresPrefix = expiresPrefix
 
     return (async () => this)()
   }
 
   async get (key) {
+    const val = await this.getExpires(key)
+    if (val && val <= new Date().getTime()) {
+      await this.remove(key)
+    }
+
     const value = this.store.getItem(key)
     return typeof value === 'string' ? value : undefined
   }
 
-  async set (key, value) {
+  async set (key, value, options = { expires: 0, isExpiresDate: false }) {
     this.store.setItem(key, value)
+
+    if (options && options.expires) {
+      // If expire exists, update or add it.
+      this.store.setItem(
+        this.expiresPrefix + key,
+        options.isExpiresDate
+          ? options.expires.toString()
+          : new Date(new Date().getTime() + options.expires * 60 * 1000)
+              .getTime()
+              .toString(),
+      )
+    } else {
+      // If it doesn't exist, remove any existing expiration
+      this.store.removeItem(this.expiresPrefix + key)
+    }
+  }
+
+  async getExpires (key) {
+    const value = await this.store.getItem(this.expiresPrefix + key)
+    return typeof value === 'string' ? +value : 0
   }
 
   async remove (key) {
     this.store.removeItem(key)
+    this.store.removeItem(this.expiresPrefix + key)
   }
 }
 
diff --git a/testing/test.html b/testing/test.html
index e9f9b86..bc51a75 100644
--- a/testing/test.html
+++ b/testing/test.html
@@ -38,7 +38,10 @@
 
     <span>Key</span><input id="key" type="text" value="keysup"><br>
     <br>
-    <span>Value</span> <input id="value" type="text">
+    <span>Value</span> <input id="value" type="text"><br>
+    <br>
+    <span>Expires</span> <input id="expires" type="text" value="0"><br>
+    <br>
     <button id="set" type="submit">Set</button>
     <button id="get" type="submit">Get</button>
     <button id="remove" type="submit">Remove</button>
diff --git a/testing/test.js b/testing/test.js
index 51e4feb..c1e7a9c 100644
--- a/testing/test.js
+++ b/testing/test.js
@@ -12,6 +12,8 @@ const cl = console.log
 const CookieStore = ImmortalDB.CookieStore
 const ImmortalStorage = ImmortalDB.ImmortalStorage
 const idb = new idbKeyval.Store('ImmortalDB', 'key-value-pairs')
+const idbExpires = new idbKeyval.Store('ImmortalDB', 'key-value-expires')
+
 
 const POLL_TIMEOUT = 300 // Milliseconds.
 const PREFIX = ImmortalDB.DEFAULT_KEY_PREFIX
@@ -40,11 +42,15 @@ function $ele (id) {
 
   const $key = $ele('key')
   const $value = $ele('value')
+  const $expires = $ele('expires')
 
   $ele('get').addEventListener(
     'click', async () => $value.value = await db.get($key.value), false)
   $ele('set').addEventListener(
-    'click', async () => await db.set($key.value, $value.value), false)
+    'click', async () => {
+      const expires = +$expires.value
+      await db.set($key.value, $value.value, { expires })
+    }, false)
   $ele('remove').addEventListener('click', async () => {
     await db.remove($key.value)
     $value.value = ''